What happened to some of the more recent threads in this sub forum? I came back to read some of the info on the tenkara on lakes thread and It as well as some others are just not here anymore. Can they be retrieved?

That tenkara thread is somewhat lost. You can see it if you have the link, like if it's in your posting history, but it's not in the forum listing. It will become visible again if someone posts to that thread.